Method for performing random access and handover

Abstract

The present disclosure relates to a 5G or pre-5G communication system for supporting a higher data transfer rate beyond a 4G communication system such as LTE. A method for controlling a cell change by a first base station according to an embodiment of the present invention comprises the steps of: generating resource information used for communication between a terminal and a second base station, when the terminal performs a cell change from a first cell corresponding to the first base station to a second cell corresponding to the second base station; and transmitting the resource information to the terminal so that the terminal and the second base station perform a random access procedure.

The invention claimed is: 
     
       1. A method for controlling handover of a user equipment (UE) by a first base station in a wireless communication system, the method comprising:
 receiving, at the first base station, a measurement report from the UE; and 
 transmitting, to the UE, a radio resource control (RRC) reconfiguration message indicating a handover to a second base station based on the received measurement report, 
 wherein the RRC reconfiguration message further includes RACH configuration information for the second base station, the RACH configuration information configured by the first base station, and 
 wherein the RRC reconfiguration message further includes CORESET configuration information of the second base station that indicates a CORESET resource of the second base station corresponding to a synchronization signal (SS) block received by the UE from the second base station. 
 
     
     
       2. The method of  claim 1 ,
 wherein the CORESET configuration information includes at least one of a CORESET start point of the second base station, a CORESET frequency location of the second base station, a number of OFDM symbols constituting the CORESET of the second base station, a CORESET transmission interval of the second base station, or SS block index information of the second base station. 
 
     
     
       3. The method of  claim 2 , wherein the CORESET frequency location includes at least one of a number of PRBs constituting the CORESET, an absolute value of a start point of the CORESET on a frequency axis, or an offset value relative to a center frequency of the frequency axis. 
     
     
       4. The method of  claim 1 , wherein the RACH configuration information is a non-contention based resource. 
     
     
       5. The method of  claim 1 ,
 wherein the SS block received by the UE from the second base station is received while the UE performs a measurement on the second base station to generate the measurement report. 
 
     
     
       6. A handover method of a user equipment (UE) in a wireless communication system, the method comprising:
 transmitting, to a first base station, a measurement report of the first base station; 
 in response to the measurement report, receiving, from the first base station, a radio resource control (RRC) reconfiguration message indicating a handover to a second base station based on the transmitted measurement report; and 
 performing a random access procedure with the second base station based on the RRC reconfiguration message, 
 wherein the RRC reconfiguration message includes RACH configuration information for the second base station, the RACH configuration information configured by the first base station, and 
 wherein the RRC reconfiguration message further includes CORESET configuration information of the second base station that indicates a CORESET resource of the second base station corresponding to a synchronization signal (SS) block received by the UE from the second base station. 
 
     
     
       7. The method of  claim 6 ,
 wherein the CORESET configuration information includes at least one of a CORESET start point of the second base station, a CORESET frequency location of the second base station, a number of OFDM symbols constituting the CORESET of the second base station, a CORESET transmission interval of the second base station, or SS block index information of the second base station. 
 
     
     
       8. The method of  claim 7 , wherein the CORESET frequency location includes at least one of a number of PRBs constituting the CORESET, an absolute value of the start point of the CORESET on a frequency axis, or an offset value relative to a center frequency. 
     
     
       9. The method of  claim 6 , wherein the RACH configuration information is a non-contention based resource. 
     
     
       10. The method of  claim 6 ,
 wherein the SS block received by the UE from the second base station is received while performing a measurement on the second base station to generate the measurement report. 
 
     
     
       11. The method of  claim 6 , the random access procedure comprising:
 transmitting, to the second base station, random access preamble based on the RRC reconfiguration message; and 
 receiving, from the second base station, an uplink grant through a resource indicated by the RACH configuration information. 
 
     
     
       12. The method of  claim 11 , further comprising:
 transmitting, to the second base station, a handover confirmation message. 
 
     
     
       13. A first base station for controlling handover of a user equipment (UE) in a wireless communication system, the first base station comprising:
 a transceiver; and 
 a controller configured to:
 control to the transceiver to receive a measurement report from the UE, and 
 control to the transceiver to transmit a radio resource control (RRC) reconfiguration message indicating a handover to a second base station based on the received measurement report, 
 
 wherein the RRC reconfiguration message further includes RACH configuration information for the second base station, the RACH configuration information configured by the first base station, and 
 wherein the RRC reconfiguration message further includes CORESET configuration information of the second base station that indicates a CORESET resource of the second base station corresponding to a synchronization signal (SS) block received by the UE from the second base station. 
 
     
     
       14. The first base station of  claim 13 ,
 wherein the CORESET configuration information includes at least one of a CORESET start point of the second base station, a CORESET frequency location of the second base station, a number of OFDM symbols constituting the CORESET of the second base station, a CORESET transmission interval of the second base station, or SS block index information of the second base station. 
 
     
     
       15. The first base station of  claim 14 , wherein the CORESET frequency location includes at least one of a number of PRBs constituting the CORESET, an absolute value of a start point of the CORESET on a frequency axis, or an offset value relative to a center frequency of the frequency axis. 
     
     
       16. The first base station of  claim 13 , wherein the RACH configuration information is a non-contention based resource. 
     
     
       17. The first base station of  claim 13 ,
 wherein the SS block received by the UE from the second base station is received while the UE performs a measurement on the second base station to generate the measurement report. 
 
     
     
       18. A user equipment (UE) for handover in a wireless communication system, the UE comprising:
 a transceiver; and 
 a controller configured to:
 control the transceiver to transmit, to a first base station, a measurement report of the first base station, 
 control the transceiver to receive, from the first base station, a radio resource control (RRC) reconfiguration message indicating a handover to a second base station based on the transmitted measurement report, and 
 perform a random access procedure with the second base station based on the RRC reconfiguration message, 
 
 wherein the RRC reconfiguration message includes RACH configuration information for the second base station, the RACH configuration information configured by the first base station, and 
 wherein the RRC reconfiguration message further includes CORESET configuration information of the second base station that indicates a CORESET resource of the second base station corresponding to a synchronization signal (SS) block received by the UE from the second base station. 
 
     
     
       19. The UE of  claim 18 ,
 wherein the CORESET configuration information a CORESET start point of the second base station, a CORESET frequency location of the second base station, a number of OFDM symbols constituting the CORESET of the second base station, a CORESET transmission interval of the second base station, or SS block index information of the second base station. 
 
     
     
       20. The UE of  claim 19 , wherein the CORESET frequency location includes at least one of a number of PRBs constituting the CORESET, an absolute value of the start point of the CORESET on a frequency axis, or an offset value relative to a center frequency. 
     
     
       21. The UE of  claim 18 , wherein the RACH configuration information is a non-contention based resource. 
     
     
       22. The UE of  claim 18 ,
 wherein the SS block received by the UE from the second base station is received while performing a measurement on the second base station to generate the measurement report. 
 
     
     
       23. The UE of  claim 18 , the random access procedure comprising:
 transmitting, to the second base station, random access preamble based on the RRC reconfiguration message; and 
 receiving, from the second base station, an uplink grant through a resource indicated by the RACH configuration information. 
 
     
     
       24. The UE of  claim 23 , the controller further configured to:
 control to the transceiver to transmit, to the second base station, a handover confirmation message.